Method and device for treating substrates

ABSTRACT

In a method for treating substrates, the substrates are lowered for treatment into a treatment fluid contained in a treatment device. The substrates are then lifted by a first receiving device at least partially out of the treatment fluid and transferred to a second receiving device for completely lifting the substrates out of the treatment fluid. The second receiving device is completely dry at the time of transfer. The drops forming at the lowest point of the substrates are drained during lifting by a drop draining element. The device for performing the method has a lifting device with a first and second receiving device and a drop draining device for draining the drops forming at the lowest point of the substrates during lifting of the substrates from the treatment fluid.

[0001] The invention concerns a method for the treatment of substrates,in which the substrates are treated in a treatment fluid and lifted in areciprocating manner with a lifting device. Furthermore, the inventionconcerns a device for treating substrates in a treatment fluid with alifting device.

[0002] A device for treating and a drying process, wherein disk-shapedsubstrates, for instance semiconductor wafers, are lifted with a liftingknife from a substrate carrier above the treatment fluid surface andinserted into guides of a hood, are known from DE 195 46 990 A1 of theapplicant of this present patent application. After the treatment fluidhas been drained from the treatment container, the dried substrates arelowered into the substrate carrier that has been dried as well and arethen removed from the device together with the carrier.

[0003] This known device and method have been successfully used inpractice. However, they are inefficient regarding the time required forthis drying process. Furthermore, for the drying of the substrates thetreatment fluid has to be drained, and this is not only time-consuming,but also requires a greater fluid consumption. Because the substrateshave to be inserted into the guides of a hood during the lifting fromthe treatment fluid, a hood of the aforementioned kind is a necessaryrequirement. However, the insertion of substrates into the guides of thehood is only possible under great difficulties and with the danger ofpossible substrate breakage, in particular for rectangular and/or squaresubstrates, or is not possible at all.

[0004] From EP 0 385 536 A1 a method and a device for drying substratesafter treatment in a fluid are known in which the substrates are guidedand secured in the guide slots of a fluid container. A lifting elementpresses the substrates that are held and guided in the guide slots ofthe fluid container in the upward direction and into an auxiliarycassette whereby the substrates, after complete removal form thetreatment fluid, still remain in contact with the lifting element thatis wetted with the treatment fluid. Drying of the substrates is thus notentirely ensured especially when the lifting element is at the same timethe securing element for the substrates and thus has a relatively largecontact area with the substrates.

[0005] Based on this, the object of the invention is the development ofa method and device for the lifting of substrates into and out of atreatment fluid that eliminate the aforementioned drawbacks ofconventional devices and, in particular, provides a fast and reliabledrying process and lifting procedure with simple means and with aminimum of expenditure, especially for rectangular and/or squaresubstrates.

[0006] The object of the invention for the aforementioned method isinventively solved by lifting the substrates with a first receivingdevice at least partially out of the treatment fluid and transfer themonto a second receiving device that is dry at the time of transfer ofthe substrates (3) to completely remove the substrates from thetreatment fluid (8). With the inventive feature, guides outside of thecontainer, for instance inside a hood, are no longer needed so thatguides inside a hood or possibly the hood itself is not required so thathandling of rectangular and/or square substrates without the danger ofsubstrate breakage is possible.

[0007] Inasmuch as the second receiving device is not already dry,according to an especially advantageous embodiment of the invention, thesecond receiving device is being dried before it receives thesubstrates. The second receiving device can advantageously be dried inthe same method step as the substrates. The already dried secondreceiving device advantageously contacts areas of substrates that havealready been dried, i.e., that are already above the fluid surface abovewhich the second receiving device is positioned during the transfer ofthe substrates.

[0008] According to another embodiment of the invention, the secondreceiving device then completely lifts the substrate areas that duringthe transfer from the first to the second receiving device were still inthe treatment fluid, out of the fluid. No substrate area that hasalready been dried, contacts a receiving area that has yet to be dried.To achieve this, according to this invention, it is not necessary todrain the treatment fluid from the fluid container.

[0009] According to an especially advantageous embodiment of theinvention, the first and second receiving devices are movable in avertical direction relative to one another, wherein a reliable, safetransfer of the substrates from the first to the second receiving deviceis ensured. During the transfer procedure, the substrates continue to belifted out of the treatment fluid with a generally constant speedwithout stops or sudden speed changes, thus minimizing the adherence ofparticles and contaminants at the substrates.

[0010] According to another very advantageous embodiment of theinvention, the drops forming on the lowest point of the substrates aredrained with a drop draining element. During the lifting of substrates,a last drop is forming on the lowest, bottom most part of the substratethat does not drain off or drains only with difficulty. By draining thisdrop with a drop draining element, this area also is dried fast andreliably.

[0011] According to another embodiment of the invention, the substratesare loaded into and/or onto the second support of the device for loadingthe device and are unloaded out of or from the second support forunloading the device. When using the inventive process, no additionalguides and no additional substrate carriers are required.

[0012] The inventive method is, in particular, advantageous inconjunction with a drying process based on the Marangoni principle,wherein a gas or a gas mixture, for example, isopropyl alcohol, nitrogenor a mixture of these gases is applied to the substrates to be dried,thus accelerating the drying process substantially.

[0013] Based on the aforementioned device, the object of the inventionis inventively further solved by providing a first receiving device tolift the substrates at least partially out of the treatment fluid and asecond receiving device to take over the substrates partially lifted bythe first receiving device, whereby the second receiving device is drywhen receiving the substrates. The benefits of this improvement areidentical to the benefits described above in conjunction with theinventive method. Here, it is also advantageous that the secondreceiving device is already dry during the transfer of the substratesfrom the first receiving device, i.e., analog to the drying process forthe substrates, has already been dried, when the second receiving deviceis also lifted out of the treatment fluid. Areas of substrates alreadydried are only contacted by already dried areas of the second receivingdevice, so that the substrates do not contact the fluid again.

[0014] Very advantageous is a drop draining element that contacts thelowest part of the substrates at least when they have been completelylifted out of the treatment fluid. For rectangular or square substrates,the lowest point of a substrate is a corner of the substrate.

[0015] According to an advantageous embodiment of the invention, thefirst and second receiving devices are respectively connected to adriven and motion-controlled transport carriage in order to

[0016] included that are being treated in a treatment fluid andsubsequently dried. The term substrates thus comprises not onlysemiconductor wafers, but also, in particular, LCD disks, compact disks,CDs, flat screens, masks, etc.

[0017] The invention as well as additional features and benefits thereofis/are described in the following with the aid of FIGS. 1 through 6schematically showing the inventive device and the step sequence of theinventive process.

[0018]FIGS. 1 through 6 schematically show a first receiving device 1with the receiving areas 1 a and 1 b as well as a second receivingdevice 2 with the receiving areas 2 a and 2 b. The embodiment showndescribes the invention in conjunction with the treatment of squaresubstrates 3 that are, as being described in this example, received inthe first receiving device 1 as well as the second receiving device 2.

[0019] A knife-shaped drop draining element 4 is connected to the secondreceiving device 2 by arms 5, 6 such that the tip 7 of the knife-shapeddraining element 4 is positioned at a constant distance to the secondreceiving device 2 and touches the lower corner of the square substrate3 when the substrates 3 are positioned in or on the receiving device 2.

[0020] Reference number 8 schematically indicates the fluid surface ofthe treatment fluid 9, into which the substrates are lowered or fromwhich the substrates are lifted.

[0021] According to FIG. 1, the device is loaded with the substrates 3by placing them from the top and above the fluid surface 8 parallel toeach other as packages onto or into the second receiving device 2. Tomaintain the substrates 3 in their parallel, vertical arrangementrelative to one another, the receiving device 2 and/or its receivingareas 2 a and 2 b are comprised of parallel extending support slots thathold the edges of the substrates 3.

[0022] The lower corners of the substrates 3 touch the tip 7 of the dropdraining element 4 that, however, initially has no function during theloading of the device, shown in FIG. 1.

[0023] After loading of the second receiving device 2 with thesubstrates 3 according to FIG. 1, the first and second receiving devices1, 2 are lowered until the substrates 3 are completely submerged in thetreatment fluid 9, as shown in FIG. 2. In this position, the substratesare treated with a treatment fluid, for instance, a rinsing agent, aspreviously described, for instance, in DE 44 13 077 A.

[0024] During or after the treatment of the substrates 3 with the fluid,the first receiving device 1 is raised relative to the second receivingdevice 2, so that the substrates 3 are positioned in or on the firstreceiving device 1 and are released from the second receiving device 2.FIG. 2 shows this state.

[0025] After the treatment of the substrates 3 in the treatment fluid 9,the first as well as the second receiving devices 1, 2 are raisedsteadily and parallel to each other to the relative position shown inFIG. 3, thus lifting the substrates 3 above the fluid surface 8 as shownin FIG. 3 to, for instance, advantageously dry them in the area abovethe fluid surface 8 utilizing the Marangoni principle, which isdescribed in EP 0 385 536 A1. In this manner, the second receivingdevice 2 with the receiving areas 2 a and 2 b is lifted above the fluidsurface 8 as well and is dried utilizing the same principle, wherein thesecond receiving device 2 does not contact the substrates 3. During thisstep, the substrates 3 are being held by the receiving device 1.

[0026] After the receiving device 2 and the edge areas of the substrates3 that have already been lifted out of the treatment fluid 9 have beendried, the first receiving device I and the second receiving device 2are moved in a relative manner to one another, so that the secondreceiving device 2 receives the substrates 3 that are consequentlyreleased by the first receiving device 1, as schematically shown in FIG.4. Thus, in this lifting area, the second receiving device 2 passes inits upwardly movement the first receiving device.

[0027] As shown in FIG. 5, the remaining areas of the substrates 3 thatwere still submerged in the treatment fluid 9, are lifted above thefluid surface 8 and dried, without interference by the first receivingdevice 1 since it is not contacting the substrates 3 during this processstep.

[0028] After the substrates 3 have been raised completely above thefluid surface 8, the draining element 4, whose tip 7 is contacting thelower corners of the substrates 3, causes the draining of the last dropson the lower corners of the substrates. FIG. 6 schematically shows thisstate as well as the position for unloading the substrates 3 that is thesame as the ready position, corresponding to position 1 a, for the nextloading procedure.

[0029] The receiving devices 1, 2 are connected to non-represented drivedevices that provide and control the travel course, the speed profile ofthe receiving devices 1, 2 and/or the relative movements of thereceiving devices 1, 2 to one another. Advantageous embodiments of such

[0030] contacts the lower edge of the square substrate 3 when thesubstrates 3 are in or on the receiving device 2.

[0031] Reference number 8 schematically indicates the fluid surface ofthe treatment fluid 9, into which the substrates are lowered or fromwhich the substrates are lifted.

[0032] According to FIG. 1, the device is loaded with the substrates 3by placing them from the top and above the fluid surface 8 parallel toeach other as packages onto or into the second receiving device 2. Tomaintain the substrates 3 in their parallel, vertical arrangementrelative to one another, the receiving device 2 and/or its receivingareas 2 a and 2 b are comprised of parallel extending support slots thathold the edges of the substrates 3.

[0033] The lower corners of the substrates 3 touch the tip 7 of the dropdraining element 4 that, however, initially has no function during theloading of the device, shown in FIG. 1.

[0034] After loading of the second receiving device 2 with thesubstrates 3 according to FIG. 1, the first and second receiving devices1, 2 are lowered until the substrates 3 are completely submerged in thetreatment fluid 9, as shown in FIG. 2. In this position, the substratesare treated with a treatment fluid, for instance, a rinsing agent, aspreviously described, for instance, in DE 44 13 077 A.

[0035] During or after the treatment of the substrates 3 with the fluid,the first receiving device 1 is raised relative to the second receivingdevice 2, so that the substrates 3 are positioned in or on the firstreceiving device 1 and are released from the second receiving device 2.FIG. 2 shows this state.

[0036] After the treatment of the substrates 3 in the treatment fluid 9,the first as well as the second receiving devices 1, 2 are raisedsteadily and parallel to each other to the relative position shown inFIG. 3, thus lifting the substrates 3 above the fluid surface 8 as shownin FIG. 3 to, for instance, advantageously dry them in the area abovethe fluid surface 8 utilizing the Marangoni principle, which isdescribed in EP 0 385 536 A1. In this manner, the second receivingdevice 2 with the receiving areas 2 a and 2 b is lifted above the fluidsurface 8 as well and is dried utilizing the same principle, wherein thesecond receiving device 2 does not contact the substrates 3. During thisstep, the substrates 3 are being held by the receiving device 1.

[0037] After the receiving device 2 and the edge areas of the substrates3 that have already been lifted out of the treatment fluid 9 have beendried, the first receiving device 1 and the second receiving device 2are moved in a relative manner to one another, so that the secondreceiving device 2 receives the substrates 3 that are consequentlyreleased by the first receiving device 1, as schematically shown in FIG.4. Thus, in this lifting area, the second receiving device 2 passes inits upwardly movement the first receiving device.

[0038] As shown in FIG. 5, the remaining areas of the substrates 3 thatwere still submerged in the treatment fluid 9, are lifted above thefluid surface 8 and dried, without interference by the first receivingdevice 1 since it is not contacting the substrates 3 during this processstep.

[0039] After the substrates 3 have been raised completely above thefluid surface 8, the draining element 4, whose tip 7 is contacting thelower corners of the substrates 3, causes the draining of the last dropson the lower corners of the substrates. FIG. 6 schematically shows thisstate as well as the position for unloading the substrates 3 that is thesame as the ready position, corresponding to position 1 a, for the nextloading procedure.

[0040] The receiving devices 1, 2 are connected to non-represented drivedevices that provide and control the travel course, the speed profile ofthe receiving devices 1, 2 and/or the relative movements of thereceiving devices 1, 2 to one another. Advantageous embodiments fordrive and lifting devices of this kind are described, in particular, inDE 195 46 990 A1 of the same applicant. This printed document isincorporated by reference into the present application to avoidrepetition concerning this embodiment.

[0041] The invention has been disclosed with the aid of a preferredembodiment and reference to schematic figures. However, to a personskilled in the art various alterations, designs and modifications areobvious without departing from the gist of the invention. For example,the inventive method and the inventive device may also advantageously beimplemented with substrates that are not square or rectangular, but haveother shapes as well, for instance, disk-shaped substrates. It is alsopossible to embody the receiving devices 1, 2 differently according tothe required use. Furthermore, the first receiving device 1 may remainbelow the fluid surface 8 and may not be lifted above it.

1. Method for the treatment of substrates (3), in which the substratesare treated in a treatment fluid (8) and lifted in a reciprocatingmanner with a lifting device, characterized in that the substrates (3)are lifted with a first receiving device (1) at least partially out ofthe treatment fluid (8) and are transferred to a second receiving device(2) and completely lifted out of the treatment fluid (8), wherein thesecond receiving device is completely dry at the time of transfer. 2.Method according to claim 1 , characterized in that the second receivingdevice (2) is dried, before it receives the substrates (3).
 3. Methodaccording to claim 1 or 2 , characterized in that the first and secondreceiving devices (1, 2) are moveable relative to one another in thevertical direction.
 4. Method according to one of the preceding claims,characterized in that the drops on the lowest point (10) of thesubstrates (3) are being drained by a drop draining element (4). 5.Device according to one of the preceding claims, characterized in thatthe substrates (3) for loading the device are loaded into or onto thesecond receiving device (2).
 6. Method according to one of the precedingclaims, characterized in that the substrates (3) for unloading areunloaded out of or from the second receiving device (2).
 7. Methodaccording to one of the preceding claims, characterized in that duringlifting out of the treatment fluid (8) the substrates (3) and/or thefirst and/or the second receiving device (1, 2) are treated with a gas.8. Device according to claim 7 , characterized in that the gas isisopropyl alcohol, nitrogen, or a gas mixture of the two.
 9. Device forthe treatment of substrates (3) in a treatment fluid (8), comprising alifting device, characterized by a first receiving device (1) forlifting the substrates (3) at least partially out of the treatment fluid(8) and a second receiving device (2) for receiving the substrates (3),wherein the second receiving device (2) during transfer of thesubstrates is dry.
 10. Device according to claim 9 , characterized inthat a drop draining element (4) is provided that contacts the lowestpoint (10) of the substrates (3).
 11. Device according to one of theclaims 9 or 10, characterized in that the substrates (3) are rectangularand the lowest point (10) of the substrates (3) is a corner (4) of thesubstrate (3).
 12. Device according to one of the claims 9 through 11,characterized in that each one of the first and second receiving devices(1, 2) is connected to a transport carriage.
 13. Device according toclaim 12 , characterized in that the transport carriages and the firstand second receiving devices (1, 2) are movable in a vertical directionrelative to one another.
 14. Device according to one of the claims 9through 13, characterized in that the travel courses and/or the liftingspeed of the transport carriages as well as their relative movementand/or relative speed to on another are controllable by at least onecontrol curve.